From 7fa2d6147efe989da2858ed81f3f5dd8a248f772 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Dietmar=20K=C3=BChl?= <dietmar.kuehl@me.com>
Date: Sun, 15 Sep 2024 08:14:27 +0100
Subject: [PATCH 1/2] added an into_expected algorithm

---
 CMakeLists.txt              |  2 +-
 examples/CMakeLists.txt     |  2 +-
 examples/demo_algorithm.hpp | 54 +++++++++++++++++++++++++++++++++++++
 examples/http-server.cpp    | 28 +++++++++----------
 4 files changed, 69 insertions(+), 17 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index cd507d9..457b51b 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -18,7 +18,7 @@ FetchContent_Declare(
     execution26
     # for local development, use SOURCE_DIR <path-to>/execution26
     GIT_REPOSITORY https://github.com/beman-project/execution26
-    GIT_TAG 5ad85cb
+    GIT_TAG 22affb6
 )
 FetchContent_MakeAvailable(execution26)
 
diff --git a/examples/CMakeLists.txt b/examples/CMakeLists.txt
index 486ffc9..e1c151f 100644
--- a/examples/CMakeLists.txt
+++ b/examples/CMakeLists.txt
@@ -13,9 +13,9 @@ set(LIBRARIES
 include(GNUInstallDirs)
 
 set(EXAMPLES
+  http-server
   empty
   server
-  http-server
   client
   task
 )
diff --git a/examples/demo_algorithm.hpp b/examples/demo_algorithm.hpp
index cb8272c..b698970 100644
--- a/examples/demo_algorithm.hpp
+++ b/examples/demo_algorithm.hpp
@@ -11,6 +11,11 @@
 #include <type_traits>
 #include <utility>
 #include <variant>
+#include <version>
+#if 202202L <= __cpp_lib_expected
+#    include<expected>
+#endif
+
 #include <iostream> //-dk:TODO remove
 
 // ----------------------------------------------------------------------------
@@ -70,6 +75,13 @@ namespace demo::detail
     template <typename T>
     using decayed_set_value_t = typename decayed_set_value<T>::type;
 
+    template <typename... T>
+    struct decayed_tuple_or_single { using type = ::std::tuple<::std::decay_t<T>...>; };
+    template <typename T>
+    struct decayed_tuple_or_single<T> { using type = ::std::decay_t<T>; };
+    template <typename... T>
+    using decayed_tuple_or_single_t = typename decayed_tuple_or_single<T...>::type;
+
     template <typename> struct make_type_list;
     template <template <typename> class L, typename... T>
     struct make_type_list<L<T...>>
@@ -99,6 +111,16 @@ namespace demo
     };
     inline constexpr into_error_t into_error{};
 
+#if 202202L <= __cpp_lib_expected
+    struct into_expected_t
+    {
+        auto operator()() const;
+        template <ex::sender Sender>
+        auto operator()(Sender&&) const;
+    };
+    inline constexpr into_expected_t into_expected{};
+#endif
+
     struct when_any_t
     {
         template <typename> struct env;
@@ -190,6 +212,38 @@ inline auto demo::into_error_t::operator()(Fun&& fun) const
 
 // ----------------------------------------------------------------------------
 
+#if 202202L <= __cpp_lib_expected
+inline auto demo::into_expected_t::operator()() const
+{
+    return beman::net29::detail::ex::detail::sender_adaptor{*this};
+}
+template <beman::net29::detail::ex::sender Sender>
+inline auto demo::into_expected_t::operator()(Sender&& s) const
+{
+    using value_type = ex::value_types_of_t<
+        Sender,
+        ex::empty_env,
+        demo::detail::decayed_tuple_or_single_t,
+        std::type_identity_t
+        >;
+    using error_type = ex::error_types_of_t<Sender>;
+    return ::std::forward<Sender>(s)
+        | beman::net29::detail::ex::then([]<typename... A>(A&&... a)noexcept{
+            return std::expected<value_type, error_type>(
+                ::std::in_place_t{}, ::std::forward<A>(a)...
+            );
+        })
+        | beman::net29::detail::ex::upon_error([]<typename E>(E&& e)noexcept{
+            return std::expected<value_type, error_type>(
+                ::std::unexpect_t{}, ::std::forward<E>(e)
+            );
+        })
+        ;
+}
+#endif
+
+// ----------------------------------------------------------------------------
+
 template <typename Receiver>
 struct demo::when_any_t::state_base
 {
diff --git a/examples/http-server.cpp b/examples/http-server.cpp
index f335c95..69578bf 100644
--- a/examples/http-server.cpp
+++ b/examples/http-server.cpp
@@ -7,6 +7,7 @@
 #include "demo_scope.hpp"
 #include "demo_task.hpp"
 #include <iostream>
+#include <expected>
 #include <string>
 #include <fstream>
 #include <sstream>
@@ -53,28 +54,25 @@ auto timeout(auto scheduler, auto duration, auto sender)
     return demo::when_any(
         std::move(sender),
         net::resume_after(scheduler, duration)
-        | demo::into_error([]{ return std::error_code(); })
-        );
+            | demo::into_error([]{ return std::error_code(); })
+        )
+        ;
 }
 
 auto make_client(auto scheduler, auto stream) -> demo::task<>
 {
     char        buffer[16];
     std::string request;
-    try{
-        while (auto n = co_await timeout(scheduler, 3s, net::async_receive(stream, net::buffer(buffer))))
-        {
-            std::string_view sv(buffer, n);
-            request += sv; 
-            if (request.npos != sv.find("\r\n\r\n")) {
-                co_await process_request(stream, std::move(request));
-                break;
-            }
-        }
-    }
-    catch (...)
+    while (auto n = co_await
+        (timeout(scheduler, 2s, net::async_receive(stream, net::buffer(buffer)))
+        | demo::into_expected()))
     {
-        std::cout << "ex: timeout\n";
+        std::string_view sv(buffer, n.value());
+        request += sv; 
+        if (request.npos != sv.find("\r\n\r\n")) {
+            co_await process_request(stream, std::move(request));
+            break;
+        }
     }
     std::cout << "client done\n";
 }

From ca3a0e73c6fc3e2212ab2f827c2b484310dc3b24 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Dietmar=20K=C3=BChl?= <dietmar.kuehl@me.com>
Date: Sun, 15 Sep 2024 15:54:48 +0100
Subject: [PATCH 2/2] restored the HTTP server example

---
 examples/http-server.cpp | 28 +++++++++++++++-------------
 1 file changed, 15 insertions(+), 13 deletions(-)

diff --git a/examples/http-server.cpp b/examples/http-server.cpp
index 69578bf..f335c95 100644
--- a/examples/http-server.cpp
+++ b/examples/http-server.cpp
@@ -7,7 +7,6 @@
 #include "demo_scope.hpp"
 #include "demo_task.hpp"
 #include <iostream>
-#include <expected>
 #include <string>
 #include <fstream>
 #include <sstream>
@@ -54,26 +53,29 @@ auto timeout(auto scheduler, auto duration, auto sender)
     return demo::when_any(
         std::move(sender),
         net::resume_after(scheduler, duration)
-            | demo::into_error([]{ return std::error_code(); })
-        )
-        ;
+        | demo::into_error([]{ return std::error_code(); })
+        );
 }
 
 auto make_client(auto scheduler, auto stream) -> demo::task<>
 {
     char        buffer[16];
     std::string request;
-    while (auto n = co_await
-        (timeout(scheduler, 2s, net::async_receive(stream, net::buffer(buffer)))
-        | demo::into_expected()))
-    {
-        std::string_view sv(buffer, n.value());
-        request += sv; 
-        if (request.npos != sv.find("\r\n\r\n")) {
-            co_await process_request(stream, std::move(request));
-            break;
+    try{
+        while (auto n = co_await timeout(scheduler, 3s, net::async_receive(stream, net::buffer(buffer))))
+        {
+            std::string_view sv(buffer, n);
+            request += sv; 
+            if (request.npos != sv.find("\r\n\r\n")) {
+                co_await process_request(stream, std::move(request));
+                break;
+            }
         }
     }
+    catch (...)
+    {
+        std::cout << "ex: timeout\n";
+    }
     std::cout << "client done\n";
 }